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  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
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  <script>

    // 数列 1 1 2 3 5 8 13 21 ....
    function feibo(n){
      if (n === 0) {
        return 0
      }
      if (n === 1) {
        return 1
      }
      return feibo(n-1) + feibo(n-2)
    }

    console.log(feibo(8));
    
  </script>
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